The English band Spacehog, led by Royston Langdon (ex-son-in-law of Aerosmith’s Steven Tyler), performed at the Harp for its 20th anniversary the other night. The act’s big single, “In the Meantime,” came out not long after the bar opened. In the crowd for the party were a pack of local musicians, including Chris Oquist, drummer for the band RIBS, and Gavin McDevitt, singer of Gentlemen Hall.